Process of manufacturing hydraulic cement



UNITED STATES PATENT OFFICE.

JAMES l3. SPEED, OELOUISVILLE, KENTUCKY.

PROCESS OF MANUFACTURING HYDRAULIC CEMEN T.

SPECIFICATION forming part of Letters Patent No. 450,750, dated April21, 1891.

Application filed February 11, 1891. Serial No. 881,075. (No specimens.)

To all whom it may concern:

Be it known that I, JAMES B. SPEED, of Louisville, county of Jefferson,State of Kentucky, a citizen of the United States, have invented anImproved Process of Manufacturing Hydraulic Cement, of which thefollowing is a full, clear, and exact specification.

My invention relates to improvements in the process of manufacturinghydraulic cement; and the object of my invention is to secure an economyboth in the fuel required for calcining the cement-rock and in the timeoccupied in the operation of burning, as Well as a uniformity in thecement product.

My invention consists in first reducing the blocks of rock as they comefrom the quarry to lumps or pieces of varying sizes, then separatingsuch lumps or pieces into groups in which, respectively, the lumps areof approximately uniform size, then charging the several said groups ofrock-lumps individually into the kiln with fuel, and finally firing thekiln, substantially as and for the purpose hereinafter set forth.

In carrying out my improved process the rock as it comes from the quarryin the form of large blocks is first reduced to lumps or pieces ofcomparatively small dimensions and of varying sizes. This may beaccomplished by passing the quarried rock-blocks through astone-breaker. l he pieces of broken rock as they come from thestone-breaker are then separated into groups in which, respectively, therock-lumps composing said groups are of approximately uniform size. Thismay be done by passing the broken rock over successive screens whichhave respectively meshes of various sizes, so that the smaller pieces ofrock of approximately uniform size will pass through and fall beneathone screen. The pieces of somewhatlarger and approximately uniformdimensions will pass through and fall beneath another screen, and so onuntil the largest pieces, approximately of uniform size, will bedischarged as tailings from the final screen of the series. Therespective groups of lumps, said lumps being, as stated, ofsubstantially uniform size in the said re spective groups, are thencharged severally and individually into the kiln with the fuel. Therespective groups of lumps may be charged severally into separate kilns,so that each kiln may contain as its entire charge lumps ofapproximately uniform size throughout mingled with the requisite fuel,or the said groups may be charged successively individually into one andthe same kiln, each group having supplied to it its requisite fuel, sothat such kiln will have as a chargegroups of lumps of uniform size insuccessive layers. It is obvious that in supplying fuel to the kiln orkilns with the said respective groups of lumps the larger lumps willrequire a larger proportion of fuel than the smaller lumps in charging.The kilns are then fired, and the operation of calcining the rock may becarried on in the well-known vertical kilns and which may be those thatwork on the single charge or continuous burning plans.

Any other known means than a stone-breaking machine may be employed toeffect the reduction of the quarry-blocks of rock to small lumps orpieces, and any other known means than screens may be used to separatethe broken rock into groups in which, respectively, the lumps are ofapproximately uniform size. The means described are named solely becausethey are believed to be preferable.

lleretofore in calcining cement-rock in kilns the rock inirregular-sized lumps or blocks has been indiscriminately charged intothe kilns, so thateach kiln contained a charge composed of rock piecesof varying sizes mingled with the fuel either in alternate layers orheterogeneously. The calcining under these conditions has of necessitybeen ununiformand the product obtained varying in quality.

By means of my described method, the broken cement rock being separatedinto groups of approximately uniform-sized pieces, respectively, thecharge of each kiln of a se ries thereof or the successive charges of asingle kiln will be composed of rock-lumps of substantially uniformsize, and hence will be uniformly calcined, and also the quantity offuel required and the period of time demanded to efiect the calcining ofeach group of uniform-sized rock-lumps may be closely predetermined,thus effecting an economyin both the fuel and the time of operation.

I am aware'that in the preparation of cement-rock for calcining the rockhas been reduced by crushing into pieces of such a fineness that therock has been approximately pulverized and so that the largest of suchpieces did not exceed in dimensions a certain predetermined size, andthat the thus-crushed rock has been then charged directly from thecrusher into a furnace, in which it was in its pulverulent conditioncalcined. I make no claim herein to such treatment of cementrock in itspreparation for calcining, and such treatment of the rock is notanalogous either in operation or result to my herein-described process.This is plainly obvious in that even in crushing the rock to a finenesswhich renders it substantially pulverulent the result will be that whilepieces will be produced the largest of which will not exceed indimensions a certain predetermined size, it will necessarily follow thatsomein fact, the larger portion-of the rock-pieces in the crushed masswill be of a less dimension than the predetermined size fixed upon forthe pieces of greatest dimensions, and hence the resultant mass ofcrushed rock will be composed of pieces which, though all ofcomparatively small dimensions, will be of varying sizes, and thesepieces of Varying sizes being charged directly and heterogeneously intoa furnace the disadvantages sought to be obviated by my describedimproved process will accrue in the resultant cement. In my improvedprocess, as herein described and to which I limit my claim herein, therock is reduced, as by breaking, to lumps or pieces of varying sizes,and these lumps are separated, as bya series of screens, into groups inwhich, respectively, the lumps are of approximately uniform size, andthese groups of uniformsized lumps are charged individually andseverally into the kiln.

What I claim as my invention, and desire to secure by Letters Patent,is-

The process of manufacturing hydraulic cement, which consists in firstreducing the blocks of rock as they come from the quarry to lumps orpieces of varying sizes, then separating such lumps or pieces of rockinto groups wherein, respectively, the lumps are of approximatelyuniformsize, then charging the several said groups of rock-lumpsseparately into the kiln with the fuel, and finally firing the kiln,substantially as and for the purpose set forth.

JAMES B. SPEED.

WVitnesses:

A. S. FITCH, A. T. FALES.

